I had a friend who had this EXACT problem with his 2003 540i sport. They kept replacing the brakes, and they kept warping. The dealership actually ended up buying him stop tech rotors, calipers, and pads--fixed the problem completely.

Wow

Best. Deal. EVER. For one of the best cars ever. Lucky~

I hate to say it, because I hate them, but yes you should contact a lemon law attorney. Specifically one of the bigger ones. You will get your money back and they will get paid by BMW.

Hell, you've already got a history and money invested into this...ask them to do the same thing for you with the brake upgrade. I'm sure financially it'd be better for the both of you as well as being a win win. Short of a failed ABS unit or a pinched/clogged brake line, I can't see why else this would be happening. Clearly if the right front is the one getting ruined all the time, something is going on with the left side since the right is doing all the work.

the rotors do not keep warping
they are badly machined , this effectively makes them warped due to the run out tolerance specified .
the X5 is sensitive to the run out , anything less than perfectly machined discs are a load of caka .
I am having issues with new discs from bmw . the run out is 0.005 " or 0.1 mm .
can`t get a straight answer from dealer as to bmw spec .
they say book it in , leave it all day , and if they find discs in spec they will invoice me for time . yet they can`t tell me run out specs so how are they going to say yes or no when I already measured run out and asked if it`s within spec or not ,, WTF :stickpoke

Another problem with turning rotors over and over again is that the thinner they become, the quicker they overheat and rewarp since there is less meat there dissipate the heat. I'm probably speaking the obvious here, but just saying.

brand new bmw discs out of the box , make sure the run out is noted before putting the calipers on , that way you can reject them , refit your old discs until you can buy something decent . the stop tech stuff sounds like a good deal .
bmw quality ????? has declined to a new low .

Replacement rotors probably aren't even made by bmw..

Supposedly most replacement rotors for BMW are made by Brembo, but even then, they probably oursource to Mexico or China as well. Until you start getting into the Stop Tech, higher ended Brembo's, etc all these lower end consumables are made by the cheapest supplier.